U.S. Pat. No.5,050,260 discloses such a machine. This known machine forms excellent enlarged heads on the protruding end of the shanks when the proportion between the length of said protruding end and the diameter of the shanks does not exceed a factor of about 2.5 and when the proportion between the diameter of the formed enlarged head and the diameter of the shanks does not exceed a factor of about 2.5. Concerning e.g. nails, for some applications, however, it is necessary with heads with such a large diameter that the proportion between the diameter of the head and the diameter of the shank will exceed the factor of 2.5. In these cases the protruding end must be so long that the proportion between its length and the diameter of the shanks also will exceed the factor of 2.5. This means that the protruding end of the shanks now will be so long that the end is liable to bend when engaging the rotating roll instead of being clenched properly to the wanted head.